Fix being able to place down in claims

src/CarriedBlock.cs

@@ -274,6 +274,8 @@ public static IEnumerable<CarriedBlock> GetCarried(this Entity entity)
 		public static bool Carry(this Entity entity, BlockPos pos,
 		                         CarrySlot slot, bool checkIsCarryable = true)
 		{
+			if ((entity is EntityPlayer playerEntity) && !entity.World.Claims.TryAccess(
+				playerEntity.Player, pos, EnumBlockAccessFlags.BuildOrBreak)) return false;
 			if (CarriedBlock.Get(entity, slot) != null) return false;
 			var carried = CarriedBlock.PickUp(entity.World, pos, slot, checkIsCarryable);
 			if (carried == null) return false;
@@ -294,6 +296,8 @@ public static bool PlaceCarried(this IPlayer player, BlockSelection selection, C
 			if (player == null) throw new ArgumentNullException(nameof(player));
 			if (selection == null) throw new ArgumentNullException(nameof(selection));
 
+			if (!player.Entity.World.Claims.TryAccess(
+				player, selection.Position, EnumBlockAccessFlags.BuildOrBreak)) return false;
 			var carried = CarriedBlock.Get(player.Entity, slot);
 			if (carried == null) return false;
 

src/Common/CarryHandler.cs

@@ -270,7 +270,6 @@ public void OnPickUpMessage(IServerPlayer player, PickUpMessage message)
 			var carried = player.Entity.GetCarried(message.Slot);
 			if ((message.Slot == CarrySlot.Back) || (carried != null) ||
 			    !CanInteract(player.Entity, true) ||
-			    !player.Entity.World.Claims.TryAccess(player, message.Position, EnumBlockAccessFlags.BuildOrBreak) ||
 			    !player.Entity.Carry(message.Position, message.Slot))
 				InvalidCarry(player, message.Position);
 		}
@@ -280,9 +279,9 @@ public void OnPlaceDownMessage(IServerPlayer player, PlaceDownMessage message)
 			// FIXME: Do at least some validation of this data.
 
 			var carried = player.Entity.GetCarried(message.Slot);
-			if ((message.Slot == CarrySlot.Back) ||
+			if ((message.Slot == CarrySlot.Back) || (carried == null) ||
 			    !CanInteract(player.Entity, (message.Slot != CarrySlot.Hands)) ||
-			    (carried == null) || !PlaceDown(player, carried, message.Selection, out var placedAt))
+			    !PlaceDown(player, carried, message.Selection, out var placedAt))
 				InvalidCarry(player, message.PlacedAt);
 			// If succeeded, but by chance the client's projected placement isn't
 			// the same as the server's, re-sync the block at the client's position.